Response of four woody ornamental species to superphosphate and controlled‐release fertilizers

Abstract

Shoot dry weights of Ilex vomitoria Ait. ‘Schellings Dwarf’, Pittosporum tobira Thunb., and Juniperus chinensis L. ‘Blue Vase’ fertilized with Sref 20N‐2P‐8K and Step (micronutrient formulation) or Osmocote 18N‐3P‐10K and Micromax (micronutrient formulation) were not different when grown in a 1 sedge peat: 1 cypress sawdust: 1 cypress shavings (v/v/v) medium with or without superphosphate. Photinia X fraseri Dress shoot and root dry weights decreased if supersphosphate was added to the growing medium and fertilized with Sref and Step, but were not different when fertilized with Osmocote and Micromax. Shoot tissue P levels of P. X fraseri and P. tobira increased with the addition of superphosphate regardless if Osmocote and Micromax or Sref and Step were used, but there was no corresponding increase in shoot dry weight. Water soluble P levels of the superphosphate amended medium with Sref and Step decreased about 70 ppm during the 6‐month experimental period.     

Impact of agricultural land use on distribution of microbial biomass and activity within soil aggregates

The presence of aggregates of various sizes in the soil is an important condition for soil carbon sequestration. In this system, microbial biomass is a key link. This work was devoted to the study of the influence of land use systems on the distribution of SOС, MB-SIR, microbial activity and eco-physiological indices (qCO₂, QR, MB-SIR/SOС and qCO₂/SOС) in relation to the size of soil aggregates. The distribution of SOС, MB-SIR and mineralization activity among the aggregates was heterogeneous. In the soil of crop rotation, high mineralization activity and MB-SIR were found in the aggregates 0.5–0.1 mm, in the monoculture soil in aggregates <0.1 mm and in the control soil in the aggregates 1–0.25 mm. There was a general trend towards a decrease in microbial activity, MB-SIR and SOС availability with an increase in aggregate size. In agricultural soils, microbial activity was determined by large aggregates (>5 mm), while in the control soil, by the aggregates 5–1 mm. Depending on the type of site and the size of aggregates, the differences in microbial metabolism were revealed. The qCO₂ and QR values decreased, and the MB-SIR/SOС and qCO₂/SOС increased in the series: control soil > crop rotation > monoculture. In the control soil, the values of the eco-physiological indices decreased with decreasing aggregate size. And vice versa, in agricultural soils, these parameters were the highest in the microaggregates (<0.25 mm). The monoculture soil, in contrast to the control soil and crop rotation soil, turned out to be more energy efficient.     

Stem productivity in relation to nitrogen concentration and carbon isotopic composition (δ13C) in leaves of hinoki cypress (Chamaecyparis obtusa Endlicher) plantations in Shikoku district,Japan

The stem productivity of the hinoki cypress (Chamaecyparis obtusa Endlicher) in relation to plant nitrogen status and water-use efficiency was investigated in the Okuono (OKU) and Karakawa (KRK) areas in Shikoku district, Japan, where abundant precipitation occurs. The nitrogen concentration and carbon isotopic composition (δ¹³C) in the leaves were used as indexes of plant nitrogen status and water-use efficiency, respectively. The leaf nitrogen concentration increased with decreasing soil carbon/nitrogen (C/N) ratio and with increasing soil pH. There was a marginally significant negative correlation between leaf δ¹³C and soil water content in the KRK area, but leaf δ¹³C in the OKU area did not correlate with the soil water condition, and increased on the upper slope. The results suggest that hinoki trees in the KRK area have higher water-use efficiency (high leaf δ¹³C) under lower soil water conditions. In the OKU area, meanwhile, leaf δ¹³C in the upper slope was higher due to adaptation to adverse conditions. When 12 plots in two areas were included, the mean height and stem increments increased with increasing leaf nitrogen concentration and with decreasing leaf δ¹³C. These findings suggest that nitrogen acquisition is a primary factor for stem productivity in the areas concerned but the productivity of some forests is restricted by the soil water condition or other conditions, as indicated by the high value of leaf δ¹³C. The measurement of nitrogen concentration and δ¹³C in leaves can provide us with valuable insights into the relative importance of nitrogen, water and other conditions on stem productivity in the two areas.     

水分对落羽杉形态结构及生长的影响

不同水分条件对落羽杉的叶子单位面积气孔数目,树干基部形态、根系分布和生长过程产生明显影响。     

不同封育措施对绵阳市低山丘陵区柏木低效林物种多样性的影响

以梓潼、盐亭两县的柏木低效林为研究对象,对各种封育技术措施对柏木低效林植物多样性的影响进行了调查研究,研究结果表明：（1）在3年封育期中,各种封育措施对柏木低效林物种多样性变化均产生不同程度的影响。其中封禁型、封补型、封调型3种类型的物种多样性和丰富度指数呈逐年上升趋势;封禁型的均匀度逐年下降,封补型和封调型的均匀度呈上升趋势。封改型的物种多样性变化最剧烈,骤降骤升,原有的物种会消失,不利于生物多样性保护。（2）对于同一群落类型来说,不同的封育措施优劣程度是不一致的;柏木纯林封育措施优劣次序为：封补型〉封调型〉封禁型。柏桤混交林封育措施优劣次序为：封禁型〉封补型。而封改型不利于生物多样性保护,因此应选择地势乎坦、土壤肥沃的地点,其经营措施应当采取大穴整地,减少对灌、草层的破坏。     

The potential of periphyton-based culture of two Indian major carps, rohu Labeo rohita (Hamilton) and gonia Labeo gonius (Linnaeus)

The effects of periphyton, grown on bamboo substrates, on growth and production of two Indian major carps, rohu, Labeo rohita (Hamilton) and gonia, Labeo gonius (Linnaeus), were studied at the Bangladesh Agricultural University, Mymensingh. For each species, five ponds were provided with bamboo substrates and five ponds without substrate (control). Ponds were stocked at a rate of 10 000 ha^?1 in both treatments. There was no discernible difference in water quality parameters between treatments. A large number of plankton (39 genera) showed periphytic nature and colonized the bamboo substrates. Rohu grew faster, resulting in a 77% higher net production (P < 0.05) in the ponds with bamboo substrates compared with the ponds without substrate. In contrast, the growth and production of gonia did not vary significantly (P > 0.05) between the substrate and control ponds. Rohu seems to be a more suitable candidate for periphyton‐based aquaculture systems than gonia.     

不同放养和管理模式对三角帆蚌生长与养殖产量的影响

2004年7月28日-10月28日在浙江省诸暨市淡水珍珠业省级科技创新服务中心枫桥实验基地通过围隔实验研究了不同放养和管理模式对1龄和2龄三角帆蚌生长与养殖产量的影响。实验中采用三种放养模式：三角帆蚌单养，三角帆蚌与鲢、鳙混养，三角帆蚌与异育银鲫混养。每种放养模式采用施肥、施肥结合投喂鱼或蚌配合饲料两种管理措施。实验开始和结束时测量三角帆蚌壳长、蚌壳宽、蚌重和鱼体重，根据蚌、鱼成活率和生长计算产量。实验结果表明：1龄和2龄三角帆蚌生长和养殖产量因放养模式而异，鱼蚌混养不仅额外获得鱼产量，同时也提高了蚌产量。两种鱼蚌混养模式相比，混养异育银鲫对1龄三角帆蚌生长较有利，混养鲢和鳙对2龄三角帆蚌生长较有利。在施肥、施肥结合投喂鱼或蚌配合饲料两种管理措施下，三角帆蚌生长和产量无明显差异。     

中医药治疗急性痛风性关节炎用药规律分析

目的 探讨中医药治疗急性痛风性关节炎的用药规律,以指导临床选方用药。方法 通过以“急性痛风性关节炎”为主题词,“中医药治疗”“中医治疗”为副主题词,检索“中文期刊数据库CNKI”2010-2015年的相关医学文献,共搜索文献216篇,其中符合条件的139篇,将纳入文献中所包括的单味中药输入Excel 2003进行一般统计学分析。结果 139篇文献中,共涉及中药复方147首,药物134味,用药频次共达1 501次,其中,用药频次前10位的药物分别是：黄柏、牛膝、薏苡仁、苍术、土茯苓、泽泻、萆薢、防己、甘草、威灵仙;药物所属类别最多的分别是：清热药、活血化瘀药、祛风湿药、补虚药、利水渗湿药。结论 清热利湿、活血通络、泄浊解毒、兼顾补虚对急性痛风性关节炎具有较好疗效。     

紫色土坡耕地退耕还林对土壤N2O排放的影响

采用静态暗箱-气相色谱法对紫色土坡耕地常规施肥处理(CL)、坡耕地不施肥处理(CL-CK)和退耕15、30年的桤柏混交林地(FL₁₅、 FL₃₀)的土壤N₂O排放通量进行为期1年的观测,同时测定土壤温度、土壤湿度、土壤无机氮含量等。结果表明,观测期内CL、CL-CK、FL₁₅与FL₃₀的N₂O平均释放速率分别是25.6、6.60、1.20、4.35 μg N₂O-N·m^-2·h^-1,CL小麦季N₂O平均释放速率是18.0 μg N₂O-N·m^-2·h^-1,玉米季35.2 μg N₂O-N·m^-2·h^-1,CL土壤N₂O排放速率显著高于CL-CK、FL₁₅和FL₃₀(P < 0.01),且CL-CK高于FL₁₅、FL₃₀(P < 0.01),FL₃₀高于FL₁₅(P < 0.01)。CL、CL-CK、FL₁₅和FL₃₀全年的N₂O排放量分别为1.01、0.400、0.050、0.310 kg N₂O-N·hm^-2。比较CL以及CL-CK的N₂O排放总量,停止施氮的措施对土壤N₂O排放的减排潜力达到0.610 kg N₂O-N·hm^-2。与CL-CK相比,FL₁₅、FL₃₀土壤N₂O释放量分别减少0.350、0.090 kg N₂O-N·hm^-2,主要原因是退耕后土壤碳氮比升高,土壤无机养分、温度以及湿度等发生变化。     

River red gum and white cypress forests in south-western New South Wales, Australia: Ecological history and implications for conservation of grassy woodlands

On the western rivers and plains of southern New South Wales, relatively small areas of forests remain in a semi-natural condition and conservation reserves are lacking. Severe drought stress in recent decades after two centuries of European management has raised issues about how best to manage these forests and, if necessary, restore them. The region was explored between 1817 and 1836. Settlers, foresters and ecologists described changes as Aboriginal culture was displaced, domestic stock, feral animals and exotic plants were introduced, rabbits were controlled, rivers were regulated, and grazing was reduced. The Aboriginal ecosystems were different to the new red gum (Eucalyptus camaldulensis) and white cypress (Callitris columellaris) forests which lack resilience. Trees, saplings, fallen timber, shrubs and parasitic plants have accumulated in recently ‘undisturbed’ sites and these features are now promoted as benchmarks for conservation. However, human activity including watering, thinning, firewood collection, grazing and/or burning may aid restoration whereas non-intervention may allow continuing degradation. This historical ecology and recent palaeoecology provide insights to conserving grassy woodlands globally.